On Tue, May 29, 2018 at 03:11:36PM +0200, Juergen Gross wrote:
> Commit 944e0fc51a89c9827b98813d65dc083274777c7f ("x86/amd: don't set
> X86_BUG_SYSRET_SS_ATTRS when running under Xen") breaks Xen pv-domains
> on AMD processors, as a prerequisite patch from upstream wasn't added
> to 4.9.
What is the prerequsite patch's git id in Linus's tree?
> Fix that by adding the prerequisite setting of X86_FEATURE_XENPV to the
> Xen pv early boot path.
>
> Cc: David Woodhouse <dwmw@xxxxxxxxxxxx>
> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> ---
> arch/x86/xen/enlighten.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 081437b5f381..674656cdb68c 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -1632,6 +1632,9 @@ asmlinkage __visible void __init xen_start_kernel(void)
> xen_init_irq_ops();
> xen_init_cpuid_mask();
>
> + /* Needed for init_amd(). */
> + setup_force_cpu_cap(X86_FEATURE_XENPV);
> +
> #ifdef CONFIG_X86_LOCAL_APIC
> /*
> * set up the basic apic ops.
> --
> 2.13.6
I'd prefer to take whatever is in Linus's tree if at all possible.
thanks,
greg k-h
